This study will investigate the virus profile of the human vascular wall by using molecular hybridization methods to detect the presence of replicating or latent viral genomes in smooth muscle cells, endothelial cells and monocytes. Localization to individual cell types will be achieved by cytological hybridization of viral probes as an adjunct to polymerase chain reaction or Southern blot detection in atherosclerotic plaque or normal vessel wall. Expression of detected viral genes will be assessed by Northern blot analysis. The viruses to be studied initially are the human herpesvirus group. The second aspect of this study is the establishment of "immortalized" cell lines of human smooth muscle cells in order to examine phenotypic changes associated with long-term proliferation of these cells, factors of potential importance in the development of atherosclerotic lesions. Finally the project will address the effect of viral infection on the expression of endothelial cell adhesion molecules.